PROJECT SUMMARY/ABSTRACT In 2009, the Food and Drug Administration (FDA) was granted authority, to reduce, but not eliminate, nicotine in tobacco products if it benefited the public health. With this authority, the FDA could test the speculation that the dose of nicotine could be reduced to a level that would not result in the addictive process usually observed with conventional cigarettes. In the proposed project, we will use behavioral economic methods to examine consumption of reduced-nicotine cigarettes within the context of the larger tobacco marketplace. These experiments will assess the abuse liability of reduced-nicotine compared to conventional cigarettes and the impact of introducing reduced-nicotine cigarettes into the larger marketplace either in addition to or instead of conventional cigarettes and address two specific aims. Specific Aim 1 is to examine the effect of nicotine concentration in tobacco and resulting plasma nicotine on laboratory behavioral economic measures of demand intensity and elasticity with a within-subject design. Specific Aim 2 is to assess behavioral economic measures of demand intensity and elasticity of cigarettes and substitution by dose in the Experimental Tobacco Marketplace under 4 conditions that mimic 2 different potential regulatory environments and 2 control conditions. The Experimental Tobacco Marketplace is a method we recently developed in our laboratory that allows experimental price manipulation while simulating real-world markets featuring a wide range of available tobacco products. This novel model will permit us to prospectively identify the possible consequences of introducing low nicotine containing cigarettes into the complex tobacco market. These studies address at least three important gaps in knowledge concerning abuse liability of reduced-nicotine cigarettes: (1) How valued are reduced-nicotine cigarettes (abuse liability), (2) Would these reduced-nicotine cigarettes be preferred and substitute for conventional cigarettes in an ever more complex tobacco marketplace, and (3) Would the introduction of reduced-nicotine cigarettes into the marketplace influence the consumption of other non-combustible nicotine products.